32
Need help or have any questions? Call us at 1-714-963-0329 or send us an email to service@globalhobby.net
After you have test-flown and done the initial trim changes to the aircraft, use the Trim Chart below to begin trimming your
airplane. Following and adhering to this chart will result in the ability to diagnose trim problems and correct those problems
using the simple adjustments shown below. Making these observations and related corrections will result in a straighter
and truer flying airplane.
TRIM FEATURE
MANEUVER
OBSERVATION
CORRECTION
SECTION 19: TRIM CHART
Control Centering
Fly general circles and random
maneuvers
Try for hands-off, straight and level flight
Readjust control linkages so the
transmitter trim levers are centered
Control Throws
Fly random maneuvers
A) Too sensitive, jerky controls
B) Not sufficient control
If A) Adjust linkages to reduce control
throws
If B) Adjust linkages to increase control
throws
Motor Thrust Angle*
From straight and level flight,
chop the throttle quickly
A) Airplane continues in a level path for a
short distance
B) Airplane pitches nose up
C) Airplane pitches nose down
If A) Engine thrust angle is correct
If B) Decrease down-thrust
If C) Increase down-thrust
Center of Gravity and
Longitudinal Balance
From level flight, roll to a 45º
bank and neutralize the controls
A) Airplane continues in the bank for a
moderate distance
B) The nose of the airplane pitches up
C) The nose of the airplane drops
If A) Trim settings are good
If B) Add nose weight
If C) Remove nose weight
Yaw**
Into the wind, do inside loops
using only elevator. Repeat test
doing outside loops from an
inverted entry.
A) Wing is level throughout
B) Yaws to right in both inside and outside
loops
C) Yaws to left in both inside and outside
loops
D) Yaws to right in inside loops and yaws
to left in outside loops
E) Yaws to left in inside loops and yaws to
right in outside loops
If A) Trim settings are good
If B) Add left rudder trim
If C) Add right rudder trim
If D) Add left aileron trim
If E) Add right aileron trim
Lateral Balance
Into the wind, do tight inside
loops
A) Wing is level and plane falls to either
side
B) Plane falls off to the left in loops.
Worsens as loops tighten
C) Plane falls off to the right in loops.
Worsens as loops tighten
If A) Trim settings are good
If B) Add weight to right wing tip
If C) Add weight to left wing tip
Aileron Rigging
With the wing level, pull to a
vertical climb and neutralize the
controls
A) Climb continues along the same path
B) Nose tends to go toward an inside loop
C) Nose tends to go toward an outside
loop
*
Motor thrust angle and center of gravity interact. Check both.
**
Yaw and lateral balance produce similar symptoms. Make certain both elevator halves are even with each other and that they both produce the same
amount of control deflection throughout the complete deflection range. Right and left references are as if you were in the cockpit.
If A) Trim settings are good
If B) Raise both ailerons very slightly
If C) Lower both ailerons very slightly
